Low-k dielectric materials are used in the formation of interconnect structures in integrated circuits. Copper lines are used in the interconnect structures. Copper lines can be formed using damascene processes, in which a Chemical Mechanical Polish (CMP) is performed for planarization. In the conventional formation processes of the interconnect structures, after the CMP, a pre-heating and a pre-treatment were performed. An organo-metallic soak was performed using Tri-Methyl-Aluminum (TMA) on the exposed surfaces of copper and the low-k dielectric layer in which the copper is disposed. A pin treatment is then performed using a bonding agent. The organo-metallic soak process and the pin treatment may be repeated. After the organo-metallic soak and the pin treatment, a dielectric etch stop layer is formed on the low-k dielectric material and copper.
The organo-metallic soak process and the pin treatment promote the adhesion of the dielectric etch stop layer to the underlying copper and low-k dielectric layer.